With the rapid development of internet, network operators generally deploy redundant links in consideration of network reliability, and the redundant links have two types, namely homogeneous ones and heterogeneous ones. Whatever type of redundant links is adopted, the redundant links and original ones are not included within the same transmission path; and under normal conditions, only one of two or more links between a source and a destination runs normally, so, huge waste of the link resources will be caused.
If the redundant links are arranged in a network, multiple Layer 2 adapters need to be provided at the source and the destination, but the protocols used on the layers above Layer 2 are the same. In addition, multiple adapters have been provided in terminals in practice. Accordingly, under packet switching manner, the problem of selecting the multiple Layer 2 adapters will occur. In the prior art, if the multiple Layer 2 adapters have the same Layer 3 address, then only one adapter is activated within a time period in the selecting process of the Layer 2 adapters, which leads to the waste of the link resources.